• Convertible bonds.
These are bonds that the investor can convert into shares of the issuing company's stock at certain times – essentially, a bond with a stock option inside. In return for this flexibility and risk reduction – afforded by the option to convert to stock when the price is high, netting gains -- the buyer tends to get lower yields. Because of the conversion option, convertibles tend to rise in value with the associated stock price. A broad spectrum of convertibles can be accessed by buying shares in convertible bond funds or in exchange-traded funds that own convertibles.

• Senior bank loans. These are investments pegged to bank financing arrangements in which the lender has the first (or senior) claim on the borrower's assets as collateral. They carry a bit more risk than most corporate bonds, but the higher yield can sometimes the extra risk. Depending on how you're structuring your fixed-income portfolio, these can play a role. For most investors, again, an ETF based on these investments is more appropriate, as they are a quick route to diversification. Examples include the Power Shares Senior Loan Portfolio, SPDR Blackstone/GSO Senior Loan ETF
and Highland iBoxx Senior Loan.

With all of these ETFs, you can set stop-loss limit
to halt sliding values promptly if the market gets bumpy and move to the sidelines in the middle of the trading day. By the same token, you can also set a limit when you buy – which could be especially helpful regarding ETFs that don't trade that many shares on a daily basis.

One factor that spurred the bond sell-off last summer was uncertainty over who the next Federal Reserve chairman was going to be. Now there's more stability because the president's nominee, Janet Yellen , if confirmed,
is viewed as likely to continue the stimulus policies of outgoing the outgoing chairman, Ben Bernanke,
so fears that the government will begin tapering stimulus in the near term have abated.

Whether any of these type of bond-related substitutes are appropriate for your portfolio depends on many factors – such as your risk tolerance, time horizon, and investment objectives just to name a few. But, if you're sitting on a lot of cash earning next to nothing, you might want to consider doing some more research to see if any are are right for you.

Given the economic uncertainty that lies ahead – the more flexible among these fixed-income investments mighht help manage risk effectively. Their liquidity allows you to quickly move holdings to cash islands like money market funds if an economic storm threatens their value.

Disclosure: As of this writing, I held positions in the SPDR Barclays Capital Convertible ETF (CWB) and the PowerShares Senior Loan Portfolio ETF (BKLN). No statement in this article should be interpreted as a recommendation to purchase any of the investments mentioned.

This column is the opinion of the author and in no way reflects the opinion of ABC News.

Byron L. Studdard, a CERTIFIED FINANCIAL PLANNER™ practitioner, is founder and president of Studdard Financial, LLC, a financial advisory firm in Sarasota, Fla., dedicated to helping clients build wealth, protect it and pass it on to future generations. Studdard is listed in the Guide to America's Best Financial Planners (published by the Consumers' Research Council of America, an independent research organization). He can be reached at Byron@studdardfinancial.com. If you have a question for him, send him an email and he will try to answer it in an upcoming column.